Such a communication system is of common general knowledge and comprises for example one master station and ten slave stations and five channels. All stations may communicate with each other using said five channels. If the master station wants to communicate with one or more slave stations, said master station being in control of the entire communication system knows which channel/channels is/are not occupied and therefore free to be used for said communication. If a slave station wants to communicate with one or more other stations, it usually asks the master station for permission thereby using one channel in a first frame, whereby said master station sends its permission to said slave station thereby using the same channel in a second frame.
This known communication system is disadvantageous, inter alia, because of being complex and time-consuming.